Self-locking centrifugal mold



May 2, 1950 A. B. HEMSTREET SELF-LOCKING CENTRIFUGAL MOLD 2 Sheets-Sheet 1 Filed Dec. 24, 1946 INVENTOR- Nber'f 5. He msfreef' May 2, 1950 HEMSTREET 2,506,216

SELF-LOCKING CENTRIFUGAL MOLD Filed Dec. 24, 1946 Y 2 Sheets-Sheet 2 INVENTOR. :lTl Alberf -Hemsfr'ee1" patented May 2, 119%6 Albert B. Hemstreet, New Hyde Park, N. Y., as-' signor to himself and Ernest 0. Rudlofl, Sr., Franklin Square, N. Y.

Application December 24, 1946, Serial No. 718,236 3- Claims. (Cl. 22--1 13.5)

This invention relates to improvements in molds of the type used in centrifugal casting machines;

An important object of this invention is to provide an automatically actuated locking mechanism by means of which the several parts from which the molds are assembled are caused to be automatically secured together during the casting operation.

A more specific object of the invention is to provide a locking means which is actuated by the centrifugal forces generated during the use of the mold in casting for locking the parts of the mold together.

Another object of this invention is to provide a heat resisting and non-conducting lining for the exposed surfaces of centrifugal molds to prevent chilling of the casting metal at the time of introduction into the mold, that is, before it fully fills all the cavities in the mold.

Other and more detailed objects of the invention will be apparent from the following description and the two embodiments thereof selected for illustration in the attached drawings.

This invention resides substantially in the combination, construction, arrangement and relative location of parts, all as will be more fully set forth hereinafter.

In the accompanying drawings: Figure 1 is a vertical central cross-sectional view through one form of mold, illustrating the non-heat conducting lining and the locking features of the invention;

Figure 2 is a top plan view of the main body portion of the mold; I

Figure 3 is a vertical central cross-sectional view through the cover portion of the mold;

' Figure 4 is a vertical central cross-sectional view through another form of mold in accord ance with this invention, showing three parts arranged to be locked together by centrifugal force; Figure 5 is a vertical central cross-sectional view of the main body portion of'the mold;

Figure 6 is a vertical central cross-sectional 2 prises a readily insertable and removable part' comprising a separate unit so that the main ma chine can be "adapted to molding articles of 'vari% ous shapes by constructing suitably shaped molds for the purpose.

It is common practice to construct these molds of several parts to facilitate the introduction of inserts, cores and the like when necessary, 'as" well as the removal of the finished casting. The common practice is to provide some form of means forlocking' the mold parts together whenv in assembled relation as, for example, by providing'them with threads by means of which they can be interconnected or with some other form of manually actuated locking device.

In accordance with an important object of this invention molds of this type are so constructed that the separable parts when at rest can be assembled and taken apart without the necessity of consciously locking the parts together and unlocking them after the casting is made. In ac-' cordance with the invention, centrifugally actu-i ated locking arrangements are provided which, of course, are normally inactive. These locking devices are so constructed that the parts can be put together and taken apart with no more effort than is required to bring them into mating relation. On the other hand, when the assembled mold is in the casting machine and revolving at the usual speeds employed in such machines, the locking devices become active to firmly se cure the parts together. As soon as the machine is brought to rest at the end of a casting operation the locks are released and the mold can be easily separated. This construction greatly simplifies and speeds up the operation of the machine.

In the die casting of most metals and particularly metals which melt at high temperatures it is common practice to heat the mold to a similarly high temperature before placing itin' the molding machine so thatwhen the molten metal is introduced into it it will not freeze and;

thereby be prevented from fully filling all of the cavities of the mold. In order that the mold retain such high temperatures sufficiently long to complete the molding operation it is necessaryto build them in relatively massive proportion.- This, in turn, requires an inconveniently long; period of heating in order to bring such relatively massive molds up to operating temperature.

In accordance with another important object of this invention linings for the exposed cavity surfaces into which the metal is molded are provided in the form of refractory poor heat con-' ducting materials such, for example, as compressed asbestos, carbon, graphite, and various other ceramic materials, known in the ceramic arts. As a result, molds provided with such linings can be made relatively much smaller since it is not necessary to heat them at all in most cases and very little in other cases.

Most of these objectsare attaine bite 011. both of thev forms of the invention, illustrated; in the attached drawings.

The mold illustrated in Figures 1, 2 and 3 is of; circular cross-sectional form at all points. It comprises a tapered spindle I adapted to be re ceived in a chuck or tapered spindle. seat. the rotatable spindle of the molding machine. One suitable form of machine with which this mold may be used is disclosed inmy copending application Serial No. 718,235; filed November 3: 1947 now abandoned. Secured to the endgoi. the; spindle I in any suitable: manner or form as an nteg al... part. th reof a. disk. 2. providedwith n a ular. recess n upper. ac iornied. by. hei erihheral lange. 3.. At. diametricallr one nosed. QQ I JZ around. the circumierehee, oi the. disk 2 are the bores 4 in each of. which is imnxisoh da. steel all 5..b.y-. swaeing. or. pinning; over heend dge of he horse m ientamount to. tet nthe ball therein. hi e perm ttin ashor io f. ts peripheral. sur ace. to. project.v bey nd. the open n lathe recess onthe end. f the. plate. 2. there isa. lining 6;. of. .efractoriz poor. heat. conducting; mate a as, o xample. ca bon. n. h ..f.orm..,of1 il-sha low c p... his cup. may. he. in. the. form. of.

a separable insert. that. can he, slipped. into. the.

neo ss nthe d i' ho plate- The. p a e a nthe o m shown. has central ounterbore 2, n. wh h e n e n tub. l t. a. core; pie e be mo ed. hede a sof con truc ion of this core piece are notgiven. sincethex form nope-rt oi the invention.bythemselves and fur.- hermore, s ce for ach di f rent. ar icle. to, be. ast. h e. co struction. man be difierent. or. 2 .9. core at all a be. used- The cover for this mold comprises two cylin- 1111....1 sec ns. 8 and 9 .seouredtogether, by means of; threads. as. shown. The. portion; 8,, is in. the torhiotan pe r nd d. r n hi e the port on.% s hthe o m f. a n hav n an end.- wall.

Mounted, in. the ap; is: a ining. l.9-,- lihewisaot lefraotom po r heat conductin material. such arbon; Th inin I omnriset.v a. senarate hav n ,v tral. pertu eb ss H: w exte ds a. sh rt distanoee hr ugh an-.... pem ;z s he hd. wa1l he an9 Wh n..t.he-1na ts -&.andi Sta e. ssembled. the. peripheraledge 8a. grins; a shoulder for locking the lining II} in th be t n ire-. oven or hetnso ripis inmat hown ure: e a n lar: sh ulder; 85ishownin heor nfi fermsztheed ezoi hei fi fil'i Q 9$ i zinplace. The. inner-wall; oi the; ring. agrrearl its lower endris-provided. withanannulair groove I 2IWhiCh1Wil1ib6 radially:- alignedwith the: ba1ls'5 as: shown.

The cavity-C in which the-metal is vast-ism? annular f orm in the particular -mold= illustrated; This mold is adapted t ca-st-a-rotororagyrocompass;motor-and therefore the laminations of the, rotor in the form of annular rings will lie around; andhe po it ne y hecore i ndjfill' thespaoe. he e aminations ha e punchedapertures which. will be aliggedwhen thus. assembledinto... hchthe. metal mokiedto famine-windin s.

A: we

and for this reason there seems to be no need to show the laminations.

When this mold is revolved at centrifugal casting speed the balls 5 move outwardly into looking engagement with the annular groove I2 holding the cover on the mold. At this time the molten metal is poured through the opening definedby the annular boss I ,I. forming part of thos lining; t0 onto the: top of the core I3 and is thrown from there by centrifugal force outwardly. The metal then works around all the unfilled areas and into the openings of the laminations; all in accordance with well known practice. Since the. space C is filled with the laminations;norefractory lining is needed for the annular; wall defining this space but should this wall be exposed because of the shape and structure of the particular object being cast a tubular lining might likewise be provided for this wall. Of course, as soon as the casting is complete and the, mold. comes. to. rest itv canv be elected. from the, machine. and taken. apart without further ado. as the, centrifugal lock is. inactive,

A brief. discussion will, be. iven. oi the. modification shown in Figures 4 to. '7,v inclusive, The purpose of. this embodiment is to show the. extent. towhichthe locking; feature. Ofthis. invention can be carried. The mold of thesefi ures. con: sists of three. p rts locked. g h r in. use by the centrifugal lock. As, before, a, tapered spindle I4. is provided. which in. this case has a cylindrical. bore therethrough. The base plate or disk I5 is attached to the. spindle M. or. is. integral therewith. as. before. and. is. provided with pairs of; diametrically arranged. bores. I6 ii whi h he balls I1 arefimprisonedas. before. The, disk. I5 is proyided witha central counter.- bore; I18 which has. an annular. groove. I9.in the wall thereof. The: core comprises a. main body portion 2. 3. and. a. central, stud 2.13. adapted. to, lie in. the, counterbore I8... Secured. to. the-central stud 2i concentrically therewith is. a shaft. 23. adaptedtolie inthebore of the, spindle IIL, This studis provided with. pairs of. diametrically opposed-.counterbores. 2I inwhich, are imprisoned, in the. manner, previously. described, the locking balls 22. The cover 25 is providedtwith an aperture extension 25. of circular. cross section through. which the. molten metal, is. poured and withan. annular recess 21 in the skirtv near one end. Thecap. is. counterboredtoform ashoulder 28 on which the upper end..of.the.p1ate-- I5 en-i ease hen the parts.- re a embled.

This mold has been designed ..to.. cast. metal around. a carbon .ring. insert CR so as to,.fi11:. the space Q in. the-mold around. this insert. The ringCRdsmounted on. theportion 24 ofthe core seas. to be accurately positioned by. it, and. the or-e s then. dropu d nt -placesd that theshaft 231185 in. th -:spindie I44. The cover, 25 iathen slipped over the. base. plate. I5 and when. this entire unit. is placedhinthe. casting machine. it wi11,.,h e seen. that. the parts become 100.k,.d2 gether. under the concentric. force generatedl. In other words, the core is locked in the base .p ate and, the, cover .is locked on the. base plate. It. is, of course, apparent. that. linings. like those previously described could: be. used, if desired, a. mold of, this; type. 7

Those skilled: in .theart .will .readily appremiatethat. the subject; matter. of this invention.- can e: embodied in many physical. forms, This is particularly true in this case because thersube iecta matter-of; the invention: is concernediwith shim aceordancewiththe wellknownpractice? is, metal molds-which: as coursegmust 135E881! ins 5 stance take a shape peculiar to the article to be cast. It follows therefore that I do not desire to be strictly limited to the disclosure but only as required by the appended claims.

What is claimed is:

1. In a centrifugal mold of the type described, the combination comprising a pair of substantially cylindrical telescoping parts forming a moulding cavity when assembled, each of said parts having at least one radial recess inthe overlapping area of the parts, and a ball held in one of said recesses and radially moveable under centrifugal force to project partially into the recess of the other part to lock the parts together.

2. In the combination of claim 1, the recess in one of said parts comprising an internal annular recess.

3. In the combination of claim 1, a core member mounted in said moulding cavity having a portion telescoping with one of said first pair of telescoped parts, said part and said core member each having at least one radially aligned recess and a ball held in one of said recesses and radially movable into the other to lock the core in place.

ALBERT B. HEMSTREET.

6 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,190,009 Reist July 4, 1916 1,320,744 DeLavaud Nov. 4, 1919 1,360,484 Wiard Nov. 30, 1920 1,486,544 Rathbone Mar. 11, 1924 1,489,036 Ladd Apr. 1, 1924 1,643,253 Mikesh Sept. 20, 1927 1,874,658 Tschudi Aug. 30, 1932 1,998,709 Dake Apr. 23, 1935 2,126,058 Taylor Aug. 9, 1938 2,174,980 Heath Oct. 3, 1939 2,290,073 Said July 14, 1942 2,299,860 Stoody Oct. 27, 1942 2,355,853 Foxon Aug. 15, 1944 2,419,716 Greenwell Apr. 29, 1947 FOREIGN PATENTS Number Country Date 154,733 Great Britain Dec. 9, 1920 

